Dr. Tarcisio C. Diaz, MD | Corona, CA | Endocrinology

.about .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

Dr. Tarcisio Diaz specializes in endocrinology, diabetes, and metabolism, with additional expertise in internal medicine. He earned his medical degree from the University of the East/Ramon Magsaysay Memorial Medical Center College of Medicine and brings five decades of clinical experience to his practice. Dr. Diaz is fluent in Spanish and Tagalog, allowing him to serve diverse patient populations.

Dr. Diaz practices at Corona Regional Medical Center and maintains offices in Corona and Riverside, California. He focuses on treating complex conditions such as type 2 diabetes, heart failure, and diabetic complications like Charcot foot. His expertise includes continuous glucose monitoring and comprehensive metabolic testing to help patients manage their diabetes effectively. Patients have given Dr. Diaz an average rating of 3.6 out of 5 stars.

AI-generated from data on this provider profile.

accepting new patients
3.6

17 Ratings
50 years of experience
45 insurance plans accepted
speaks Spanish, Tagalog
Univ Of The East/Ramon Magsaysay Memorial Medical Center College Of Med
5 written reviews
2 specialties
9 areas of expertise
2 board certifications
1 hospital affiliation
3 office locations
Male

17 ratings & reviews

Sort:

Showing 1 to 5 of 5 reviews

.rating-and-reviews .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

Wait w/ appt. 2 hrs. Do to their over Schedule. Staff rude!! Dr. W/ patient for a few Min. Very unprofessional staff. U pay $85 for Consultation and 5 min w Dr. Attention. Unhappy Patient!!!

October 23rd, 2013

.rating-and-reviews .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

I went in and all the staff is new and they dont know what there are doing!! I was told I couldn't be seen I had to wait! They didnt even know how to call in my medication! I don't know what happen!! I have been going to Dr Diaz for years and now I am changing!

November 20th, 2012

.rating-and-reviews .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

Dr diaz's office is excellent...he saved my mothers life....I sometimes have to wait awhile but the wait is well worth it..staff is friendly and has helped me many times with medications...there always busy but they always try their best to get things done..

August 30th, 2012

.rating-and-reviews .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

I would not reccomend this Dr.or office. The staff is rude, office hours are terrible and the Dr does not give me the confidence that he knows what he is doing. I am waiting for blood results andd the office is closed for 2 weeks, did nnot tell me or have thhe courtesy to call and let me know what my blood test results are. Very unprofessional for a Dr's office to close for 2 weeks with pending test results to report.

January 27th, 2011

.rating-and-reviews .noScriptHide .nojs-show,.truncated [data-rem],blockquote .truncated-text{ display: initial !important}.no-js-hide,.ellipsis { display: none; }.truncated:after {content: '' !important}

Dr. Diaz is a good doctor technically. However, he is very unorganized and doesn't seem to care that his office is disfunctional. A typical wait has been 1 to 2 hours. His appointment scheduler is rude, argumentative, indifferent, and not to be relied on.

December 13th, 2010

Diaz Tarcisio Office

900 S Main St Ste 100Corona, CA 92882

Tel: (951) 738-9081

Mon9:00 am - 5:00 pm

TueClosed

Wed9:00 am - 12:00 pm

Thu9:00 am - 12:00 pm

FriClosed

Sat9:00 am - 12:00 pm

SunClosed

Corona Regional Medical Center

800 S Main StCorona, CA 92882

Tel: (951) 737-4343

Mor Healthcare

9041 Magnolia AveRiverside, CA 92503

Mon8:00 am - 5:00 pm

Tue8:00 am - 5:00 pm

Wed8:00 am - 5:00 pm

Thu8:00 am - 5:00 pm

Fri8:00 am - 5:00 pm

SatClosed

SunClosed


Dr. Tarcisio Calibo Diaz, MD	Dr. Ricardo Rafael Vega, MD	Dr. Hammad Omer Khan, MD	Dr. Leslie Sison Aquino, MD
Endocrinology, Diabetes & Metabolism	Critical Care Medicine	Interventional Cardiology	Pediatrics
Accepts New Patients		Accepts New Patients
3.6 (17 Ratings)	5 (5 Ratings)	4 (4 Ratings)	4.8 (5 Ratings)
50 Years of Experience	35 Years of Experience	26 Years of Experience	45 Years of Experience
No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option
Speaks Spanish, Tagalog	Speaks Spanish, English	Speaks English, Spanish	Speaks English
Corona , CA	Temecula , CA	Upland , CA	Fontana , CA
Med School: Univ Of The East/Ramon Magsaysay Memorial Medical Center College Of Med	Med School: Universidad Nacional De San Agustin Facultad De Medicina	Med School: Aga Khan University Medical College	Med School: University Of The Philippines Manila College Of Medicine
Current Profile	View Profile	View Profile	View Profile

Search for your insurance and plan

Check-up
Diabetes
Heartburn
Immunization
Internal Medicine
Physical
Vaccination
Weight Loss
Weight Loss (non-surgical)

MEDICAL LICENSE

Medical Doctor, California, 2026, Active

EDUCATION & TRAINING

Medical School

Univ Of The East/Ramon Magsaysay Memorial Medical Center College Of MedGraduated in 1976

Dr. Ara Ararat Chrissian, MD
Critical Care Medicine
23 Years Exp | Loma Linda, CA
(1)
Dr. Ellen Dongjoo Gim, MD
Hospital Medicine
37 Years Exp | Fountain Valley, CA
(7)
Dr. Charles Nguyen, MD
Nephrology
15 Years Exp | Eastvale, CA
(0)
Dr. Hannah Cho Nien, MD
Diagnostic Radiology
17 Years Exp | TORRANCE, CA
(0)
Dr. Rebecca Sahar Ahdoot, MD
Nephrology
13 Years Exp | Orange, CA
(1)
Dr. Mitchell Alan Berner, MD
Neuroradiology
20 Years Exp | Beverly Hills, CA
(0)
Khoa Anh Dang
Nurse Practitioner
| Chino, CA
(0)
Dr Shelley Bath
Diagnostic Radiology
23 Years Exp | Fountain Valley, CA
(1)
Dr. Faranak Sadri Tafazoli, MD
Diagnostic Radiology
30 Years Exp | Riverside, CA
(3)
Dr. Vinod Nigam, MD
Diagnostic Radiology
35 Years Exp | Riverside, CA
(1)

Which hospitals is Dr. Tarcisio Diaz affiliated with?: Dr. Tarcisio Diaz is affiliated with Corona Regional Medical Center.
Does Dr. Tarcisio Diaz accept my insurance?: You can see the insurance plans that Dr. Tarcisio Diaz accepts on their Vitals profile.
How can I make an appointment with Dr. Tarcisio Diaz?: You can find contact information for Dr. Tarcisio Diaz here on Vitals.
Where is Dr. Tarcisio Diaz's office located?: Dr. Tarcisio Diaz's office is located at 900 S Main St Ste 100, Corona, CA, 92882.
What languages does Dr. Tarcisio Diaz speak?: Dr. Tarcisio Diaz speaks Spanish and Tagalog.

Our provider data is gathered directly from physicians and publicly available databases. Providers who verify their profiles gain the ability to update information, offering additional details about their specialties,education, treated conditions, performed procedures, and accepted insurances.

Reviews on Vitals are submitted by users only. Recognizing the valuable insights these reviews offer into a doctor's reputation, we maintain internal policies and protocols to ensure the quality and accuracy of all reviews. Importantly, providers cannot delete or alter reviews independently. Reviews can only be deleted or changed following an internal assessment by our customer service team.

Your feedback is highly valued and we encourage you to contact our support team should you encounter any issues.

Copyright © 2026 Vitals Consumer Services, LLC. US Patent No. 8, 694, 441. All Rights Reserved.
As more fully set forth in this website's terms of use . (1) nothing contained on or offered by or through this website should be construed as medical advice and should not be relied upon for medical diagnosis or treatment. Vitals Consumer Services, LLC ("Vitals"). the provider of this website, does not recommend or endorse any particular healthcare provider whose information or ratings appear on this website; and (2) Vitals has granted you a limited license to access and use this website for your own noncommercial use. You are not permitted to copy, reproduce, distribute, transmit, mirror, frame, scrape, extract, wrap, create derivative works of, reverse engineer, decompile or disassemble any part or aspect of this website.